This invention relates to packaging materials and, more particularly, to a composite package for shipping and storing explosive items.
The need to transport commercial quantities of devices containing explosive material gives rise to concerns regarding the safety with which packages containing such devices can be moved and stored. It is important to provide proper packaging of such devices because the packages (and their contents) may be exposed to a wide range of temperatures and may be subjected to a variety of physical stresses, e.g., impacts that occur should the package be dropped or jostled. In designing a packaging system for such items, attention must be given not only to preventing unwanted initiation of the items in the package, but also to the prevention of the propagation of inadvertent initiation of items in one package to those in another.
The degree to which these objectives are met by a packaging system has practical, legal and commercial significance.
The present invention pertains to a composite package system that provides sufficient protection and containment of eight explosive devices that contain 33 grams each (264 grams total) of RDX explosive or the equivalent thereof, such as HMX, HNS, etc., to qualify for a U.S. Department of Transportation (DOT) classification of 1.4S. The composite package system of this invention comprises the combination of a prior art corrugated paper box in a wooden crate that meets DOT 4C1 requirements and that is lined with cement-fiber material.
Accordingly, the present invention provides a container for explosive materials comprised of cardboard, wood and a cement-fiber material.
According to one aspect of the invention, the cement-fiber material may comprise portland cement and cellulose fiber, optionally in an amount of about 5 to 10 percent cellulose fiber. In one embodiment, the container may have sufficient strength to contain the detonation therein of a plurality of explosive devices comprising a total of 320 grams of explosive material.
In a particular embodiment, the wood may comprise a wooden crate which measures about 36.8 centimetersxc3x9736.8 centimetersxc3x9730.5 centimeters (14.5 inchesxc3x9714.5 inchesxc3x9712 inches) and which comprises pine board having a thickness of about 1.9 centimeters (xc2xe inch); and may be cement-fiber material at the bottom of the container having a thickness of about 10 centimeters (4 inches), cement-fiber material at the sides of the container having a thickness of about 2.5 centimeters (1 inch), and cement-fiber material at the top of the container having a thickness of from about 3.1 centimeters (1xc2xc inches) to 4 centimeters (1{fraction (9/16)} inches); and there may further be at the bottom of the container three layers of cardboard having a bursting strength of about 200 pounds per square inch (xe2x80x9c200 psi cardboardxe2x80x9d) and a layer of 250 psi cardboard, and at each side of the container three layers of 275 psi cardboard and a layer of 250 psi cardboard, and comprising at the top of the container two layers of 275 psi cardboard and a layer of 250 psi cardboard. Optionally, the 250 psi cardboard may comprise a cardboard box in the crate.
In a specific embodiment of the invention, there may be a plurality of cement-fiber material at the bottom of the container, at each side of the container, and at the top of the container. Optionally, the 250 psi cardboard may comprise a cardboard box in the crate.
This invention also relates to a package comprising a plurality of explosive devices enclosed in a container as described herein. Optionally, the devices may comprise a total of not more than about 320 grams of explosive material. There may be, for example, from about 264 to 320 grams of explosive material.
According to another aspect of the invention, the package may contain eight devices and each device may be disposed in a positioning tube. Four of the positioning tubes may be disposed in a first array in the container and four of the positioning tubes may be disposed in a second array above the first array. Preferably, the devices in the second array are not vertically directly above devices in the first array.
The present invention also relates to a method for packaging a plurality of explosive devices, the method comprising enclosing the devices in a container as described herein.